1. Field of the Invention
This invention relates generally to novel, metal-containing thiocarbamate additives for functional fluids, e.g., lubricating oils, automatic transmission fluids (ATF's), as well as fuel compositions. This invention more specifically relates to metal compounds, complexes and compositions of thiocarbamates derived from hydrocarbyl primary amines. These metal compounds, complexes, oligomers and compositions are useful as additives which impart improved anti-wear properties, anti-oxidant properties, extreme pressure properties, and friction modifying properties in functional fluids for internal combustion engines.
2. State of the Art
As those skilled in this art are aware, additives impart special properties to functional fluids, particularly lubricants and fuel. They may give these fluids new properties or they may enhance properties already present. One property all lubricants have in common is the reduction of friction between materials in contact. Nonetheless, the art constantly seeks new materials to enhance such friction properties.
Carbamate additives for functional fluids, particularly molybdenum-containing and tungsten-containing carbamate additives for lubricant and fuel compositions have been disclosed in the patent literature and reported in the technical literature.
For example, U.S. Pat. Nos. 4,395,343; 4,402,840; 4,285,822; 4,265,773; 4,272,387; 4,369,119; 4,259,195; 4,259,194; and 4,283,295 all to DeVries and King disclose a variety of molybdenum sulfur and nitrogen containing compounds including dithiocarbamates which are useful as anti-oxidant additives for lubricant compositions. While some of these patents disclose dithiocarbamate metal compounds including molybdenum, all of these compounds, however, are derived from secondary amines according to methods previously described in the art.
U.S. Pat. No. 4,315,826 to Schlicht et al. describes molybdenum dithiocarbamate compounds useful as anti-wear and anti-oxidant additives for lubricating compositions. These compounds are prepared by treating a thiomolybdenum derivative of an alkenylsuccinimide with carbon disulfide.
A molybdenum dihydrocarbyldithiocarbamate compound useful as an additive for lubricants is disclosed in U.S. Pat. No. 4,098,705 to Sakurai et al. This compound is derived from a secondary amine.
In U.S. Pat. No. 3,509,051 to Farmer et al., various molybdenum dialkyldithiocarbamates are disclosed which are derived from secondary amines. These compounds are disclosed as being useful as anti-oxidant and anti-wear additives for lubricating oils.
Metal dithiocarbamates wherein the metal may be molybdenum are disclosed in U.S. Pat. No. 4,479,883 to Shaub et al. as being useful in combination with an ester of a polycarboxylic acid and a glycol or glycerol to provide improved friction reducing properties in lubricating compositions. Complexes of molybdenum oxides and sulfur- and nitrogen-containing moieties which include dialklydithiocarbamates, which have utility as additives for lubricants, are disclosed in U.S. Pat. No. 3,419,589 to Larson et al. and U.S. Pat. No. 4,164,473 to Coupland et al.
U.S. Pat. No. 4,474,673 discloses sulfurized molybdenum-containing friction modifying additives for lubricating oils which are prepared by reacting a sulfurized organic compound having an active hydrogen or potentially active hydrogen with a molybdenum halide.
U.S. Pat. No. 3,541,014 to LeSuer discloses molybdenum complexes of Group II metal-containing compounds, e.g., overbased Group II metal sulfonates, which impart improved extreme pressure properties and anti-wear properties to lubricant compositions.
The review article to Lashkhi et al. in Khimiya i Tekhnologiya Topliv i Masel, Number 12, Pages 33-35, December, 1983, discloses various oil-soluble molybdenum compounds including dithiocarbamates which are useful as friction modifying agents to result in lower fuel consumption in internal combustion engines.
Novel sulfur and phosphorus containing molybdenum compositions which are useful for improving fuel economy for internal combustion engines are disclosed in U.S. Pat. No. 4,289,635 to Schroeck.
U.S. Pat. No. 4,266,945 to Karn discloses molybdenum-containing compositions which are derived from a molybdenum compound, phenol and an amine which compositions are disclosed as being useful as additives in lubricants and fuels.
None of the foregoing disclosures teach nor even suggest a molybdenum carbamate compound, complex or composition which has been derived from a primary amine and which further improves anti-wear properties, anti-oxidant properties, extreme pressure properties and friction modifying properties for functional fluids in general and specifically for lubricant compositions.